Today, news of the shootings at Lone Star College broke on Twitter and spread across the internet before any traditional news outlet reported the news.

But back in 1973 — 40 years ago today — CBS News anchor Walter Cronkite broke the news of former President Lyndon Johnson’s death on live TV in a very different way. CBS TV went live with its star anchor, known as “the most trusted man in America,” as he was talking on the telephone to LBJ’s spokesman, Tom Johnson (who later was my publisher at the Dallas Times Herald).

Johnson told Cronkite — and Cronkite alone — the news of the legendary Texan’s sudden death of a massive heart attack. Cronkite relayed the news, including details of the desperate flight to Brooke Army Medical Center hospital in San Antonio. He was holding a telephone receiver to his ear as he appeared live on the air.

Take a look at the video. It looks so retro. But it tells you so much about the difference between news then — when media giants like Cronkite ensured that only confirmed facts made it to the air — and today’s 24/7 world, where rumors and unsubstantiated tweets form our first draft of history.